/*
  Stream.h - base class for character-based streams.
  Copyright (c) 2010 David A. Mellis.  All right reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

  parsing functions based on TextFinder library by Michael Margolis
*/

#ifndef Stream_h
#define Stream_h

#include <inttypes.h>
#include "Print.h"

// compatability macros for testing
/*
#define   getInt()            parseInt()
#define   getInt(ignore)    parseInt(ignore)
#define   getFloat()          parseFloat()
#define   getFloat(ignore)  parseFloat(ignore)
#define   getString( pre_string, post_string, buffer, length)
readBytesBetween( pre_string, terminator, buffer, length)
*/

// This enumeration provides the lookahead options for parseInt(), parseFloat()
// The rules set out here are used until either the first valid character is found
// or a time out occurs due to lack of input.
enum LookaheadMode {
    SKIP_ALL,       // All invalid characters are ignored.
    SKIP_NONE,      // Nothing is skipped, and the stream is not touched unless the first waiting character is valid.
    SKIP_WHITESPACE // Only tabs, spaces, line feeds & carriage returns are skipped.
};

#define NO_IGNORE_CHAR  '\x01' // a char not found in a valid ASCII numeric field

class Stream : public Print {
    protected:
        unsigned long _timeout;      // number of milliseconds to wait for the next char before aborting timed read
        unsigned long _startMillis;  // used for timeout measurement
        int timedRead();    // private method to read stream with timeout
        int timedPeek();    // private method to peek stream with timeout
        int peekNextDigit(LookaheadMode lookahead, bool detectDecimal); // returns the next numeric digit in the stream or -1 if timeout

    public:
        virtual int available() = 0;
        virtual int read() = 0;
        virtual int peek() = 0;

        Stream() {
            _timeout = 1000;
        }

        // parsing methods

        void setTimeout(unsigned long timeout);  // sets maximum milliseconds to wait for stream data, default is 1 second
        unsigned long getTimeout(void) {
            return _timeout;
        }

        bool find(const char* target);   // reads data from the stream until the target string is found
        bool find(const uint8_t* target) {
            return find((const char*)target);
        }
        // returns true if target string is found, false if timed out (see setTimeout)

        bool find(const char* target, size_t length);   // reads data from the stream until the target string of given length is found
        bool find(const uint8_t* target, size_t length) {
            return find((const char*)target, length);
        }
        // returns true if target string is found, false if timed out

        bool find(char target) {
            return find(&target, 1);
        }

        bool findUntil(const char* target, const char* terminator);   // as find but search ends if the terminator string is found
        bool findUntil(const uint8_t* target, const char* terminator) {
            return findUntil((const char*)target, terminator);
        }

        bool findUntil(const char* target, size_t targetLen, const char* terminate, size_t termLen);   // as above but search ends if the terminate string is found
        bool findUntil(const uint8_t* target, size_t targetLen, const char* terminate, size_t termLen) {
            return findUntil((const char*)target, targetLen, terminate, termLen);
        }

        long parseInt(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
        // returns the first valid (long) integer value from the current position.
        // lookahead determines how parseInt looks ahead in the stream.
        // See LookaheadMode enumeration at the top of the file.
        // Lookahead is terminated by the first character that is not a valid part of an integer.
        // Once parsing commences, 'ignore' will be skipped in the stream.

        float parseFloat(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
        // float version of parseInt

        virtual size_t readBytes(char* buffer, size_t length);  // read chars from stream into buffer
        size_t readBytes(uint8_t* buffer, size_t length) {
            return readBytes((char*)buffer, length);
        }
        // terminates if length characters have been read or timeout (see setTimeout)
        // returns the number of characters placed in the buffer (0 means no valid data found)

        virtual size_t readBytesUntil(char terminator, char* buffer, size_t length);  // as readBytes with terminator character
        size_t readBytesUntil(char terminator, uint8_t* buffer, size_t length) {
            return readBytesUntil(terminator, (char*)buffer, length);
        }
        // terminates if length characters have been read, timeout, or if the terminator character  detected
        // returns the number of characters placed in the buffer (0 means no valid data found)

        // Arduino String functions to be added here
        String readString();
        String readStringUntil(char terminator);

    protected:
        long parseInt(char ignore) {
            return parseInt(SKIP_ALL, ignore);
        }
        float parseFloat(char ignore) {
            return parseFloat(SKIP_ALL, ignore);
        }
        // These overload exists for compatibility with any class that has derived
        // Stream and used parseFloat/Int with a custom ignore character. To keep
        // the public API simple, these overload remains protected.

        struct MultiTarget {
            const char* str;  // string you're searching for
            size_t len;       // length of string you're searching for
            size_t index;     // index used by the search routine.
        };

        // This allows you to search for an arbitrary number of strings.
        // Returns index of the target that is found first or -1 if timeout occurs.
        int findMulti(struct MultiTarget* targets, int tCount);
};

#undef NO_IGNORE_CHAR
#endif